The present invention relates to clamps for hoses or the like. More particularly, the invention relates to improvements in clamps of the type wherein a loop-shaped intermediate portion of a flexible metallic or plastic strap is adapted to be placed around a portion of a hose or a like body consisting of deformable material and the intermediate portion can be tightened around the hose to prevent leakage between the internal surface of the hose and the external surface of a nipple or a like device which extends into the end portion of the hose. Still more particularly, the invention relates to improvements in clamps of the type wherein the loop-shaped intermediate portion can be tightened around a hose without resort to screws or other types of threaded tightening elements.
It is already known to provide a clamp of the above outlined character with a loop-shaped intermediate portion which has a row of inwardly extending teeth mating with one or more external teeth on a first end portion of the strap. A second end portion of the strap can be pulled in a direction to reduce the size of the loop-shaped intermediate portion, i.e., to tighten the intermediate portion around one end of a hose or the like. When the tightening action is not produced in response to rotation of a screw (note commonly owned U.S. Pat. No. 4,244,088 granted Jan. 13, 1981 to Heinz Sauer) which is rotatable in a bracket or lug of the second end portion and meshes with an internally threaded lug on the intermediate portion of the strap, the second end portion is normally formed with an outwardly bent lug which can be urged in a direction to reduce the size of the intermediate portion whereby the teeth of the intermediate portion slide along the tooth or teeth of the first end portion until the application of the tightening force is terminated, until the lug of the second end portion breaks away, or until the lug is bent into the general plane of the second end portion so that it cannot offer an effective surface for the application of a tensioning force. Reference may be had to commonly owned copending U.S. patent application Ser. No. 258,375 filed Apr. 28, 1981 by Heinz Sauer et al. (corresponding to German Offenlegungsschrift No. 30 17 178). This copending application discloses a clamp which does not employ a tightening screw and wherein the lug constitutes an outwardly bent free end or tip of the second end portion of the strap. The thickness of the bent-over lug is identical with the thickness of the remaining parts of the strap. It is also proposed to reinforce the lug by ribs or webs in the region where the lug extends from the remaining part of the second end portion of the strap. Such webs or ribs stiffen the lug and enable it to stand more pronounced stresses prior to yielding and moving into the general plane of the second end portion. It has been found that such lugs are often incapable of standing the stresses which must be applied to adequately tighten the loop-shaped intermediate portion of the strap around a hose or the like. Moreover, the application or making of webs or ribs involves additional expenditures in time and material so that the cost of such clamps is at least as high as that of clamps which employ screws or analogous threaded tightening elements.